Vehicles of the type utilized in motor sports, for example NASCAR races, are precision machines which require constant and precise gauging, adjustment, alignment and the like. Taking just the wheels of the vehicle as one example, the wheels are subject to rotational deviations about a horizontal axis and a vertical axis, and to linear deviations with respect to each other.
More particularly, the wheels of the vehicle may be subject to "toe-in/toe-out" which occurs when the wheels are pivoted about a vertical either clockwise or counterclockwise. Such a condition results in the front and rear edges of the wheel lying in a plane other than one which is perpendicular to a longitudinal axis of the axle to which the wheel is attached. The wheels may also be subject to a condition known as "camber." This condition occurs when the wheels are pivoted about a horizontal axis either clockwise or counterclockwise. This condition results in the top and bottom edges of the wheel residing in a plane other than one which is perpendicular to the longitudinal axis of the axle to which the wheel is attached. Finally, the wheels may be subject to "offset" wherein the linear distances between the rear wheels and the front wheels differ, the linear distances between the left-hand wheels and the right-hand wheels differ, or either the front wheels or back wheels are shifted laterally relative to the other.
Contrary to what one would normally intuitively think, it is desirable in such a racing vehicle to have certain amounts of camber, toe-in/toe-out, and offset. In fact, all of these parameters can be fine tuned to a specific race track in order to optimize the performance of the racing vehicle for that track. However, before these parameters can be precisely fine tuned to maximize the vehicle's performance on a particular track, one must be able to first accurately measure each of these parameters.
One rather crude method which has been utilized to take various measurements from the vehicle has been to utilize a number of individual lengths of string or twine attached to various points of the automobile, for example, axles, wheels, chassis, engine and the like. For a plumb bob effect a weight is secured to the bottom end of each of these strings. Then, various measurements may be taken from the strings to various points on the vehicle structure with, for example, a tape measure. As can be appreciated, such a method is rather tedious, time consuming and less than precise.
An improvement upon this prior technique has purportedly been devised by CD Products and is referred to as its "CD Laser Alignment Tool" in an advertisement in a trade publication. That ad states that this device is used to align a rear end housing under a race car. The ad illustrates a laser (understood by the applicant to be a "point" laser which projects a linear laser beam which appears as a dot on a surface in the path of the beam) attached to one end of an arm, with the other end of the arm being mounted to a wheel hub.
It would be desirable to improve upon the CD Products Laser Alignment Tool to better facilitate establishment of various vehicle datums from which to take various precision measurements in order to be able to fine tune various parameters of the vehicle to optimize the vehicle's performance for a specific racing track.